I haved read your question, and i known you resolved this problem, i have problem same as you, in service structure, service OPC_DA is initialize, not service. Can you help me!
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The 800xA OPC DA Connector service will remain in "Initialize" until the OPC server has entered "OPC_SERVER_RUNNING".
The AC800 OPC server enters running state when at least one controller has been successfully connected.
Verify that the AC800 OPC server has at least one "smiley" face on the OPC DA tab.
The above picture also shows the 800xA's advdsopcclient.exe tool with which you can probe an OPC server's state with.
The controller need to have a program downloaded to it from Control Builder M as well.
Furthermore the AC800 OPC server needs some files to be able to go online with a controller. This only works if the OPC server runs under an account with access permission in the 800xA system where the Control Builder M node also need to be connected to.
First open the OPC server configuration panel and connect to one of the controllers on which the download is to be performed.See that you get a yellow smiley.
Second perform a download from the CBM to that controller.This should work.
One common mistake that most make is go to the OPC_connector service in the service structure and check if it is enabled.